Most commercial golf balls bear marks or symbols indicative of a trade name or play number on their surface. Prior art marking methods include (1) the use of transfer tape, (2) stamping, (3) pad printing also known as curved surface printing in which an ink image is transferred once from a block copy to a pad and then from the pad to a golf ball, and (4) inscription of a mark on the cavity of a golf ball forming mold. However, all these methods have drawbacks.
(1) The use of transfer tape is based on heat transfer with the risk of leaving substantial deformation on the ball surface due to heat and pressure applied, detracting from the sphericity and dimple precision of the ball. If the mark is of large size, poor adhesion often occurs because of non-uniform bonding forces or air bubble trapping. It is then necessary to protect the mark with a coating film on the ball surface. (2) Method of stamping balls is by either stamping balls through inked tape or applying an inked stamp against balls. In either case, the ink used is likely to blur and ooze, failing to provide an aesthetically acceptable finish. Since ink has to invade the ball surface, stamping can often detract from the sphericity of the ball. (3) Pad printing requires an extra step of preparing a block copy and the adhesion of marks is poor. In printing on curved surfaces like golf ball surfaces, the pattern is often distorted failing to achieve an aesthetically acceptable finish. (4) Mold inscription is a laborious operation and the application of ink on every molding cycle requires a number of steps. This method is quite difficult to carry out in practice.
There exists a demand for a novel golf ball marking method which eliminates the drawbacks of these prior art methods.